### Abstract

The electrohydrodynamic instability leading to convection in nematic liquid crystals can be a Hopf bifurcation with two oblique pairs of counterpropagating traveling rolls. Due to the anisotropy of the physical system, the correct amplitude equations for this instability are four globally coupled Ginzburg Landau equations, whose coefficients can be computed from the weak electrolyte model of Kramer and Treiber. Some aspects of the solutions of this Ginzburg Landau system are discussed and related to experiments.